The invention relates to apparatus for implanting mandrils, catheters or other elongated slender objects into the cavities of animal bodies, for example, into human hearts. More particularly, the invention relates to improvements in apparatus for arterial or interavenous implantation or for implantation by way of other body cavities. Still more particularly, the invention relates to improvements in apparatus which employ flexible guide wires.
A drawback of presently known implanting apparatus which employ guide wires is that they present problems when the path for implantation is irregular, e.g., if a vein or artery exhibits one or more pronounced curvatures, especially if the path is narrow or very narrow. If the guide wire or the leading end of the object to be implanted is pointed, it is likely to penetrate into and to injure the tissue on its way toward the ultimate destination. For example, the leading ends of many surgical electrodes constitute or include helices with sharp tips. Therefore, certain presently known electrodes include hollow sheaths into which the helical leading ends are retracted during introduction through a vein or another body cavity. Such electrodes must be equipped with complex and expensive mechanisms for expulsion or propulsion of retracted leading ends prior to anchoring in a selected portion of the body cavity, e.g., in a portion of a human heart. Moreover, the retracted leading end of a conventional electrode of the just outlined character is likely to be stiff or practically stiff which renders it difficult or impossible to introduce such electrode into and through an artery or vein.
Many arteries or veins are anatomically configurated, or are distorted (particularly narrowed) as a result of a disease, in such a way that they are practically or totally impassable to a conventional electrode, catheter or mandrin, especially if the leading end of the object to be implanted is relatively stiff. In fact, the resistance to penetration can be so pronounced that an attempt to introduce an electrode or a catheter can entail injury to the tissue and/or damage to or even total destruction of the object which is to be implanted.
Presently known guide wires are designed to extend through openings in the objects to be implanted. This contributes to the bulk, cost and rigidity of the objects and renders it even more difficult to implant the objects through narrow arteries or veins.
German Pat. No. 34 42 736 to Bonzel discloses an expansible catheter including a balloon having an inner shell which is slidable along a guide wire and an outer shell. The space between the two shells can receive a fluid.
German Pat. No. 30 10 743 to Witzel et al. discloses a similar balloon with inner and outer shells which forms part of an apparatus for the treatment of esophagus. The balloon surrounds and is movable along a gastroscope.
German published patent application No. 1 491 697 of Edwards discloses a flexible catheter with a bowden wire and a guide wire.